In this article we examine results of a mixed-longitudinal study of child and adolescent growth among agropastoral Karimojong children in Moroto District, northeast Uganda. During a 5-month period from August to December, 2004, longitudinal data were collected for a mixed sample of 104 Karimojong children, aged from birth to 18 years. During a previous study in 1998–1999,we had measured 26 of these children who then ranged in Age between 3 months and 7 years. Most of the children were small and thin relative to accepted growth standards, and prevalence of stunting and wasting in childhood was high. In the period from the end of childhood through adolescence, however, Karimojong girls showed marked variability in annual growth, with some attaining a large adult size relative to what we predicted based on their poor childhood growth. Developmental, evolutionary, and environmental determinants are considered. We conclude that growth of these children reflects exposure to environmental insults that vary unpredictably within relatively short intervals. Variability in the magnitude and timing of these insults among children from different birth-cohorts is probably sufficient to account for so-called “shifting” of growth percentiles in childhood and adolescence in this mixed sample. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc.